William c



(No Model.)

W. G. HOMAN.

SUSPENSION DEVICE FOR LAMPS.

No. 408,107. Patented July 30, 1889.

UNITED STATES PATENT OFFICE.

\VILLIAIWI CEHOMAN, C1 MERIDEN, CONNECTICUT, ASSIGNOR TO EDWARD MILLER &COMPANY, OFSAME PLACE.

SUSPENSION DEVICE FOR LAMPS.

SPECIFICATION forming part of Letters Patent No. 408,107, dated July 30,1889.

Application filed April 1, 1889. Serial No. 305,536. (No modeh) ing alamp-supporting har Fig. 2, a top view of the suspension device,aportion of the auxiliary frame broken away for convenience ofillustration, enlarged; Fig. 3, a side View of the principal andauxiliary frame, show ing vertical section of the spring-drum and dog, aportion of the frame broken away; Fig. 4, a sectional side view, cuttingat right angles to Fig. 3; Figs. 5, (5, and '7, modifications.

This invention relates to an improvement in that class of devices forsuspending lamps from the ceiling, in which a spring-drum is employed,arranged upon an axis, with two or more chains or cords wound upon thesaid drum under the reaction of the spring, the lamp, or whatever it maybe, attached to said chains, so that drawing down the lamp will impartrotation to the drum to wind the spring, and then the reaction of thespring aids in raising the lamp or thing suspended.

As the variation in weight of the thing suspended is very great, and itis impractical to construct the suspending devices so that the power ofthe spring of the same fixture will be adapted to such varying weight ofthings suspended, some device is necessary which will engage thespring-drum and prevent its rotation, except when it is desired to raiseor lower the thing suspended, for without such provision thespring-drum, being constructed with a power to support agiven weight, ifthat weight be heavier, would not be able to hold the thing suspended atany other elevation than its lowest point; or, on the contrary, if thething suspended be much lighter than the power of the spring, then thething so suspended could be held only at its highest point of elevation;hence the necessity of some auxiliary power or engaging device upon thedrum which will hold it to prevent its rotation except at times when theadjustment is desirable, and at any point 7 within the range of thevertical adjustability.

The object of my invention is to provide a locking device for the drum,whereby it may be rigidly held at any point to which the adjustment maybe made, so as to prevent the possible reaction of the spring to draw upthe thing suspended, but yet permit easy disengagement, so that thepower of the spring may be brought into action to lift or aid in liftingthe thingsuspended.

To this end the invention consists, principally, in hanging the frame ofthe springdrum upon an axis at right angles to the axis 011 which thedrum revolves, and so that a rocking movement may be imparted to saiddrum, combined with a dog eccentrically arranged about the axis of thedrum, the drum provided with a corresponding bearing-surface, with whichsaid dog is adapted to engage when thrown outward by its eccentricity,or from which it may be relieved as the dog is withdrawn from suchengagement by such eccentricity, the said rocking movement of So thedrum and a spring being adapted to throw the said dog into and out ofengagement with said drum, and as more fully heroinafter described.

A represents the frame, which carries a vertical axis 13, on which thespring-drum C is arranged, as usual in this class of fixtures;

1), the suspending-loop by which the fixture may be hung to the ceiling,or wherever it may be desirable. This loop is attached to 0 or formed asa part of an auxiliary frame E, which frame extends down each side thedrum.

The frame A is hung to the auxiliary frame E upon pivots F,diametrically opposite each other and at right angles to the plane ofthe axis upon which the drum revolves. These pivots F should be near thelower end of the drum. Upon the upper head of the drum a concentricflange G is formed. The axle B extends upward and terminates above thedrum in an eccentric projection or trunnion H. Upon this eccentric H adog I is hung, projecting radially outward toward the flan ge G, as seenin Fig. 2. A spring J is applied between the frame A and the dog, thetendency of which is to turn the dog upon its eccentric H in thedirection to withdraw its nose from engagement with the flange G, asrepresented in Fig. 2, but yet permit the dog to be turned on itseccentric to giveit an outward or radial movement to bring its nose intoengagement with the flange G, as represented in broken lines, Fig. 2.

As here represented, the frame A is constructed' with uprights K L, onwhich pulleys M are arranged, over which chains or cords applied to thedrum run in the usual manner to the thing to be suspended, these pulleysserving as guides for the proper laying of the chain upon the drum.

The spring J is represented as a torsional spring coiled around theeccentric, one arm in engagement with the dog and the other inengagement with the upright K; but the particular arrangement of thespring is immaterial, it only being essential that there shall be aspring, the tendency of which is to throw the dog out of engagement withthe drum.

The rotation of the drum under the reaction of the springthat is, inwinding the chains onto the drum-is in the direction of the arrowindicated in Fig. 2, when the dog is thrown outward, so as to engage theflange G. Under such engagement the tendency of the spring underreaction is to turn the dog in the same direction as the drum isrevolving; but because of the eccentricity of the dog with relation tothe axis of the drum the dog can only turn until a positively-forcedengagement is made between the drum and the dog. Then further reactionwill be prevented, because of the cramp-like action of the dog upon thedrum. Consequently, in such position the drum will stand and hold thedog in engagement; but if the drum be rotated in the opposite direction,as by pulling down the thing suspended, the dog will accordingly returnuntil disengaged from the drum. Then the springJ of the dog operates tothrow the dog to its positively disengaged position, as represented inFig. 2.

The auxiliary frame E is provided with two downwardly-projecting studs NO, which eX- tend down opposite sides of the dog I. The dog isconstructed with a shoulder P on one side, corresponding to the stud Nof the frame E, and upon the opposite side the dogis con structed with alike shoulder R, corresponding to the stud O on the frame E, theseshoulders P R of the dog being upon opposite sides of their respectivepins and on the side in opposition to the action of the dog-spring, sothat the said studs N 0 form stops against which the dog will be broughtunder the action of its own spring when disengaged from the drum, asbefore described and as seen in Fig. 2. This completes the construction.

The operation is as follows: Suppose the drum to stand in its horizontalposition, as seen in Fig. 1,with the dog held back against its stops andout of engagement with the drum, as represented in Fig. 2. Now thespring-drum is free to rotate in either direction, so that the thingsuspended may be drawn down or raised, as may be desirable; but when thedesired position is attained, to engage the drum in that position,so asto insure the thing suspended remaining at that point, the drum isturned upon its pivots FF, so as to bring it to the inclined position,as represented in broken lines, Figs-1 and 4. Under this operation theauxiliary frame E does not move. The studs 0 N consequently remainstationary, but the dog rocks with the drum, and as such rocking of thedrum throws the eccentric to one side or the other, according to thedirection in which the rocking is produced, it necessarily follows thatthe stop 011 the frame E will operate against the corresponding shoulderof the dog I and turn it accordingly, and as the shoulders of the dogare upon that side of the stops in the direction in which the dog mustturn to be engaged with the drum, it follows that under such swingingmovement the dog will be turned upon its eccentric, as indicated inbroken lines, Fig. 2, and until its nose is brought into engagement withthe flange of the drum. hen the dog is in such position for engagement,the pulling down of the thing suspended causes a rotation of the drum inthe direction opposite to the arrow, Fig. 2, the dog readily yieldingfor such rotation without substantially opposing the movement of thedrum; but as soon as the force which was pulling down is removed thenthe reaction of the spring-drum tends to turnthe drum in the directionof the arrow, Fig. 2,

and to force the engagement with the dog.

lonsequently the dog produces a cramp upon the drum, and so long as thatcramp is maintained the reaction of the spring of the drum is prevented,and while the dog is thus engaged the spring-drum may be brought back toits horizontal position, and there remains, suspending the lamp or thingat the point to which it may have been adjusted, as described.

To release the engagement of the dog with the drum so as to permit thereaction of the spring, a slight pull down upon the chains will turn thedrum in the direction opposite to that of the reactive force of thespring, and with it the dog. The dog, turning upon its eccentric, iswithdrawn from its engagement with the drum, and as soon as it is freefrom such engagement the reactive force of the spring J throws the dogbackward against its stops and out of engagement with the drum, so thatnow the drum is free to rotate in either direction for readjustment ofthe thing suspended, and when such readjusted position is attained thedrum and its frame are rocked again, as before, to bring the dog intoengagement to lock the drum.

ICC

I represent the dog as making frictional engagement with the flange; butit willbe understood that any of the known equivalents for afriction-dog to operate upon the drum may be employedas, forillustration, a pawl and ratchet, the pawl being hung upon the frame, asseen in Fig. 5 5 but so that the stops, under the rocking movement ofthe drum, will bring the pawl into engagement with the ratchet, asindicated in broken lines, Fig. 5. This simple illustration, as oneknownequivalent for the dog, will be sufficient to enable others skilled inthe art to apply other known equivalents.

As a convenient means for imparting the rocking movement to the drum,the harp of the lamp-frame is constructed with its two sides S T hingedto opposite sides of the fountsupport U, as at a a, Fig. 1. These sidesT extend upward and are connected to an evener Z), the two chains (Zfrom the drum being connected to the same eveners at the two pointsabove. Now when it is desired to give the rocking movement to the drumfor the purpose of making the engagem entbefore described, one side ofthe harp is pulled downward, as indicated in broken lines, Fig. 1, whichimparts corresponding movement to the evener Z) and corresponding riseto the opposite side S of the harp. This movement operates upon thedrum-frame through the chains and correspondingly turns the drum uponits pivots, as also indicated in broken lines, Fig. 1. Be cause ofhinging the two sides of the harp to the fount-support. and theintroduction of the evener between the drum-chains, this up-anddownmovementmaybe produced from either side of the harp, and when free thenatural gravity of the parts will bring the frame back to its normalposition and so that the fount will hang horizontally. The rockingmovement of the drum, however, maybe otherwise impartedsay in caseswhere the lamp or thing suspended is hung to a hookccentrally betweenthe chains, as in 6, a cord or chain f may be arranged extendingdownward within convenient reach, by the pulling of which theinclination of the drum will be produced, as indicated in Fig. 6. Inthis case, the suspension being central between the chains, the drumwill naturally turn to its horizontal position when free so to do.

I represent the dog as constructed with two shoulders and the auxiliaryframe with two corresponding bearing-points. This permits the drum to berocked in either direction, with the same result of locking the drum;but one such engagement may be omitted, the other being sufficient,except. that the engagement will be made only from one sidethat is, byrocking the drum in one direction only.

In some cases it may be desirable to hold the drum constantly locked,and so as to be unlocked by the rocking movement of the drum, instead ofholding the drum unlocked and looking it by the rocking movement, asdescribed. In such case it is simply a reversing of the operation ofthedog, as seen in Fig. 7, the dog being in the engaged positionnormally and disengaged by the rocking of the drum, as indicated inbroken lines, same figure. In the latter case the disengagement isproduced by the rocking of the drum in the opposite direction to that inthe first illustration.

I claim 1. In a suspension device for lamps and like purposes, thecombination of a principal frame, a spring-drum hung upon an axle insaid principal frame, an auxiliary frame by which the said device isadapted to be suspended, the said principal frame hung tothe auxiliaryframe upon an axis at right angles to the axis upon which the drumrevolves, and whereby the said drum. and its axle are permitted aroekingmovement, and an engaging device between said auxiliary frame and thesaid drum, substantially as deseribed,whereby under such rockingmovement of the drum the said engaging device is brought into actionwith the drum to prevent the reactive force of the spring-drum.

2. In a suspension device for lamps and other articles, the combinationof a principal drum, an axle stationary in said frame, a springdrumarranged to revolve upon said axle, the axle extending through the drumand constructed. at its project-ing end with an eccentric, an auxiliaryframe to which the principal frame is pivoted upon an axis at rightangles to the axis upon which the drum revolves, the said auxiliaryframe serving as a means for suspending the device, the head of the drumaround the eccentric end of the axle constructed with a concentricengaging-surface, a locking-dog between said engagingsurface and saideccentric, the said locking-dog constructed with one or .more shoulders,and the auxiliary frame with bearing-points corresponding to saidshoulder or shoulders, and with which points said shoulders are adaptedto engage under a rocking movement imparted to said drum, with a springarranged to yieldingly hold the said dog out of engagement with thedrum,substantially as described.

The combination of the principal frame A, carrying a stationary axle B,the springdrum 0, hung upon said axle, the axle extending through thedrum and terminating above in an eccentric 11, an auxiliary frame E,hung to said principal frame upon pivots forming an axis upon which thesaid drum may swing at right angles to the axis upon which the drumrevolves, a dog I, hung upon said eccentrio II, the end of the drumconstructed with a concentric flange G, within which said dog isarranged, the dog constructed with one or more shoulders and theauxiliary frame with corresponding bearing-points with which saidshoulders of the dog are adapted to engage as the drum is rocked, with aspring applied to said dog, the reactive force of which is adapted tohold the said dog yieldingly out of engagement with the drum, but permitits IIO engagement with the drum under a rocking movement of the drum,substantially as described.

4. The combination of a frame provided with an axle, a spring-drumarranged to revolve on said axle, an auxiliary frame by which the saiddrum maybe suspended, the frame of the drum hung to the said auxiliaryframe on an axis at right angles to the axis on which the drum revolves,and whereby the drum is permitted a rocking movement at right angles tothe axis of its revolution, an engaging device between the said drum andauxiliary frame adapted to in terlock with the drum under such rockingmovement, and two chains running from the said drum to an evener, and towhich evener the thing to be suspended may be hung, substantially asdescribed.

5. The combination of a frame provided with an axle, a spring-drumarranged to revolve on said axle, an auxiliary frame by which the saiddrum maybe suspended, the frame of th e drum hung to the said auxiliaryframe, and whereby the drum is permitted a rocking movement at rightangles to the axis of its revolution, an engaging device between thesaid drum and auxiliary frame adapted to interlock with the drum undersuch rocking movement, two chains running from said drum downward, anevener constructed with two points of connection, and to which saidchains are attached, and the evener constructed with two other points ofconnection below said two chain points of connection, and a harp forsuspending alamp composed of two sides and a fountrlng, the said twosides hingedto the said fountring and, extending upward, attached to thesaid two other points on the evener, substantially as described.

WM. 0. I'IOMAN.

Nitnessesz' FRED C. EARLE,

J. H. SHUMWAY.

